The present invention relates to an airbag apparatus which inflates and deploys airbags by uniforming the gas flow even when only some of a plurality of inflators are activated.
A conventional airbag apparatus equipped in a vehicle comprises an inflator (gas generator), an airbag which deploys by receiving a gas generated by the inflator upon collision or crash, a storage case which includes a synthetic resin cover member that covers the inflator and the surface side of the airbag, and the like. When collision detection means such as an acceleration sensor or the like detects any collision, the inflator is activated to release a gas into the airbag, and the airbag breaks the cover member and deploys into a passenger room, thus protecting a passenger.
When the airbag inflates by the gas flow released forward from the inflator, the bag surface violently hits the passenger, resulting in a large shock. For this reason, in order to deflect sideways the gas flow released from the inflator, Japanese Patent Laid-Open No. 8-11659 has proposed a technique in which a diffuser that deflects sideways the gas flow released from one inflator is provided to cover a gas inlet so as to suppress the airbag from excessively inflating forward while inflating the airbag quickly in the right-and-left direction.
However, an airbag apparatus which comprises a plurality of inflators can eliminate injury of a passenger resulting from a shock of the airbag that deploys at high speed, by activating some inflators, e.g., when the shock speed is low. As shown in FIG. 11, when a left inflator 151a of two inflators 151a and 151b is activated, the gas flow released from a left opening 155a of a diffuser 155 becomes stronger than that released from a right opening 155b, and an airbag 152 often deploys nonuniformly.
The present invention has been made in consideration of the aforementioned problems, and has as its object to provide an airbag apparatus which can uniformly deploy an airbag by uniforming and releasing the gas flow even when only some of a plurality of inflators are initiated.
In order to solve the aforementioned problems and to achieve the above object, according to the first invention, since a rectifying member for uniforming the gas flow released from a gas outlet is provided between the gas outlet and a gas flow deflection member, the gas flow can be uniformed and released even when only some of a plurality of inflators are initiated, and an airbag can uniformly deploy without any local offset.
According to the second invention, since the rectifying member has a plurality of openings having different areas, and the opening area corresponding to an inactive inflator is larger than that corresponding to an active inflator to decrease the opening area of the rectifying member on the active inflator side, the gas can easily flow toward the opening of the rectifying member on the inactive inflator side, thus uniforming the gas flow.
According to the third and fifth inventions, since the gas flow deflection member has a plurality of openings which have different areas and are formed on its side portions, and the opening area corresponding to an inactive inflator is larger than that corresponding to an active inflator to decrease the opening area of the gas flow deflection member on the active inflator side, the gas can easily flow toward the opening of the gas flow deflection means on the inactive inflator side, thus uniforming the gas flow.
According to the fourth invention, since the gas flow deflection member breaks upon activating a plurality of inflators, it breaks by the release pressure of the gas and can uniformly release the gas flow toward the airbag.
According to the sixth invention, since the rectifying member comprises a varying member for varying the opening area of the rectifying member, and the varying member moves to change the area of a gas outlet so as to reduce the opening area of the rectifying member on the active inflator side, the gas can easily flow toward the opening of the rectifying member on the inactive inflator side, thus uniforming the gas flow to the airbag.
According to the seventh invention, since the varying member comprises a varying plate which is moved by the gas flow to vary the opening area of the rectifying member, and the varying plate moves to change the area of the gas outlet to reduce the opening area of the rectifying member on the active inflator side, the gas can easily flow toward the opening of the rectifying means on the inactive inflator side, thus uniforming the gas flow toward the airbag.
According to the eighth invention, since uniforming means for uniforming the gas flow released from a gas outlet is provided between the gas outlet and gas flow deflection means, the gas flow can be uniformed and released even when only some of a plurality of inflators are initiated, and an airbag can uniformly deploy without any local offset.
According to the ninth invention, in the informing means, since the area of an opening, corresponding to an inactive inflator, of a plurality of openings formed on side portions of the gas flow deflection means is smaller than that corresponding to an active inflator so as to reduce the opening area of the uniforming means on the active inflator side, the gas can easily flow toward the opening of the rectifying means on the inactive inflator side, thus uniforming the gas flow toward the airbag.
Other objects and advantages besides those discussed above shall be apparent to those skilled in the art from the description of a preferred embodiment of the invention which follows. In the description, reference is made to accompanying drawings, which form a part thereof, and which illustrate an example of the invention. Such example, however, is not exhaustive of the various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention.